Peracetic acid type sterilizers have heretofore been used for sterilizing or pasteurizing food containers. In aseptically filling beverages, in particular, it is important that the containers, the contents and the filling environment are all made aseptic and, therefore, the peracetic type sterilizer has been used for sterilizing or pasteurizing the containers such as bottles and caps (patent document 1, etc.).
The peracetic acid type sterilizer comprises chiefly peracetic acid, acetic acid and hydrogen peroxide which are present in an equilibrium state. If the concentration of hydrogen peroxide is high, however, the hydrogen peroxide tends to stay in the container and it becomes necessary, after the sterilization, to wash the container with aseptic water to a sufficient degree. Further, it has been desired to suppress the concentration of the peracetic acid to be lower than the concentration that used to be employed in the customary methods.
To solve the above problem, there has been proposed a pasteurizing method using a sterilizing composition that comprises hydrogen peroxide, percarboxylic acid and carboxylic acid and that further contains 20 to 250 ppm of a catalase enzyme that is capable of decomposing the hydrogen peroxide (patent document 2).
According to the pasteurizing method that uses a sterilizing composition comprising hydrogen peroxide, percarboxylic acid and carboxylic acid and, further, containing the catalase enzyme, there is obtained such an advantage that the hydrogen peroxide is decomposed due to the catalase enzyme, the concentration of the hydrogen peroxide is lowered in the sterilizing composition, and efficient sterilization is realized maintaining stable sterilizing power for extended periods of time as a result of controlling the concentration of the hydrogen peroxide.